Double-type baffle plate shell-and-tube heat exchanger

Abstract

The invention discloses a double-type baffle plate shell-and-tube heat exchanger. The heat exchanger comprises a heat exchanger cylinder, a shell pass inlet connecting pipe, a shell pass outlet connecting pipe, an end socket and a heat exchange pipe, and baffle plates are arranged in the heat exchanger cylinder and comprise circular ring baffle plates and shutter baffle plates; heat exchange tube holes for the heat exchange tubes to penetrate through are formed in the annular baffle plates, heat exchange tube holes for the heat exchange tubes to penetrate through are formed in the shutter baffle plates, and the annular baffle plates and the shutter baffle plates are alternately arranged at intervals. According to the double-type baffle plate shell-and-tube heat exchanger, the annular baffle plates and the shutter baffle plates are alternately arranged in the heat exchanger cylinder at intervals, the flowing state of shell pass fluid can be changed, shell pass heat exchange is enhanced, and the shutter baffle plates and the annular baffle plates are alternately arranged in the heat exchanger cylinder at intervals, so that the heat exchange efficiency is improved. On one hand, the flow dead zone of a traditional baffle plate in the heat exchanger is effectively reduced, the pressure drop of shell pass fluid is reduced, on the other hand, the supporting effect on the heat exchange tube is improved, and vibration generated by fluid induction is reduced.

Description

Technical Field

[0001] This invention belongs to the field of heat exchanger technology, specifically relating to a dual-type baffle shell-and-tube heat exchanger. Background Technology

[0002] Shell-and-tube heat exchangers, as a type of heat transfer device, are key components for energy utilization, especially for low-grade energy. They are widely used in many industrial sectors, including power and energy. The use of shell-and-tube heat exchangers can improve the overall utilization rate of thermal energy, thereby reducing energy consumption, increasing production efficiency, and improving the efficiency of heat exchangers. This plays an important role in reducing energy consumption levels in high-energy-consuming industries and promoting carbon emission reduction. The flow state of the shell-side fluid and the tube-side fluid is an important factor affecting the heat exchange performance of shell-and-tube heat exchangers. In the practical application of traditional disc-annular baffle shell-and-tube heat exchangers, the shell-side fluid causes significant pressure loss and dead zones, thus limiting the overall heat exchange efficiency.

[0003] Therefore, a new type of shell-and-tube heat exchanger is needed. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a dual-baffle shell-and-tube heat exchanger. The dual-baffle shell-and-tube heat exchanger of this invention can reduce the flow dead zone, lower the flow resistance of the shell-side fluid, and improve the heat exchange efficiency of the shell-and-tube heat exchanger.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A dual-type baffle shell-and-tube heat exchanger includes a heat exchanger shell, a shell-side inlet pipe, a shell-side outlet pipe, a head, and heat exchange tubes. Baffles are arranged inside the heat exchanger shell, including annular baffles and louvered baffles. The annular baffles have heat exchange tube holes for the heat exchange tubes to pass through, and the louvered baffles also have heat exchange tube holes for the heat exchange tubes to pass through. The annular baffles and the louvered baffles are arranged alternately at intervals.

[0007] The number of the annular baffles is equal to the number of the louvered baffles.

[0008] The louvered baffle includes an annular shell, a fixing rod, and blades. The fixing rod is disposed between the blades and the annular shell, and the side of the blades is in contact with and fixed to the annular shell.

[0009] There are four fixing rods, with two fixing rods respectively provided on the upper and lower parts of the annular shell.

[0010] The plane of the annular baffle is perpendicular to the length direction of the heat exchange tube, and the blades of the louvered baffle are inclined relative to the length direction of the heat exchange tube.

[0011] The angle between the blades of the louvered baffle and the length direction of the heat exchange tube is 45 degrees.

[0012] The louvered baffle has three blades, and the three blades have the same tilt direction and tilt angle, with the blades placed in the center.

[0013] In the dual-type baffle shell-and-tube heat exchanger, the shell-side fluid first contacts the annular baffle and then the louvered baffle.

[0014] The heat exchanger shell has a partition plate inside the left end cap, which works with the left tube sheet to divide the left end cap into two chambers. A tube inlet pipe is provided at the upper end of the left end cap, and a tube outlet pipe is provided at the lower end of the left end cap.

[0015] The heat exchange tubes are circular tubes, and all the heat exchange tubes are arranged in an equilateral triangle pattern.

[0016] The beneficial effects of this invention are as follows:

[0017] (1) The dual-type baffle shell-and-tube heat exchanger of the present invention can change the flow state of the shell-side fluid and enhance shell-side heat transfer by alternately setting annular baffles and louvered baffles inside the heat exchanger shell. The alternating arrangement of louvered baffles and annular baffles inside the heat exchanger shell effectively reduces the flow dead zone in the traditional baffle shell-and-tube heat exchanger and reduces the pressure drop of the shell-side fluid. On the other hand, it improves the support for the heat exchange tubes and reduces the vibration induced by the fluid.

[0018] (2) The present invention further provides fixing rods on the upper and lower parts of the louvered baffle plate, which can strengthen the blades and improve the stability of the blades, and can also turbulent the fluid as it passes through the upper and lower parts of the louvered baffle plate, thereby enhancing shell-side heat transfer. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a dual-type baffle shell-and-tube heat exchanger according to the present invention;

[0020] Figure 2 This is a cross-sectional schematic diagram of a dual-type baffle shell-and-tube heat exchanger according to the present invention;

[0021] Figure 3 This is a schematic diagram of the left end cap structure of a dual-type baffle shell-and-tube heat exchanger according to the present invention;

[0022] Figure 4 This is a schematic diagram of the louvered baffle structure of a dual-type baffle shell-and-tube heat exchanger according to the present invention;

[0023] Figure 5 This is a schematic diagram of the annular baffle structure of a dual-type baffle shell-and-tube heat exchanger according to the present invention;

[0024] Figure 6 This is a Nusselt number curve diagram of a dual-type baffle shell-and-tube heat exchanger according to the present invention;

[0025] Figure 7 This is a shell-side pressure drop curve of a dual-type baffle shell-and-tube heat exchanger according to the present invention;

[0026] Figure 8 This is a PEC (potential energy) curve, which is a comprehensive performance evaluation of the present invention.

[0027] The attached figures are labeled as follows: 1. Heat exchanger shell; 2. Shell-side inlet nozzle; 201. Shell-side outlet nozzle; 3. Left end cap; 301. Right end cap; 4. Left tube sheet; 401. Right tube sheet; 5. Annular baffle; 6. Louvered baffle; 7. Divider plate; 8. Tube-side inlet nozzle; 801. Tube-side outlet nozzle; 9. Heat exchanger tube; 10. Heat exchanger tube hole; 11. Fixing rod; 12. Blade; 13. Annular shell. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0029] See Figure 1 and Figure 2A double-baffle shell-and-tube heat exchanger includes a heat exchanger shell 1, a shell-side inlet pipe 2, a shell-side outlet pipe 201, end caps, a tube sheet, and heat exchange tubes 9. The end caps include a left end cap 3 and a right end cap 301, and the tube sheet includes a left tube sheet 4 and a right tube sheet 401. The heat exchange tubes 9 are disposed inside the heat exchanger shell 1, with the left tube sheet 4 and right tube sheet 401 located at their ends. The left end cap 3 is located on the outer side of the left tube sheet 4, and the right end cap 301 is located on the outer side of the right tube sheet 401. The shell-side inlet pipe 2 is located at the lower right end of the heat exchanger shell 1, the shell-side outlet pipe 201 is located at the upper left end of the heat exchanger shell 1, the tube-side inlet pipe 801 is located above the left end cap 3 of the heat exchanger shell 1, and the tube-side outlet pipe 801 is located below the left end cap 3 of the heat exchanger shell 1. The heat exchanger shell 1 is separated from the end caps on both sides by tube sheets on both sides. The tube sheets are provided with heat exchange tube holes 10. The two ends of the heat exchange tube 9 are respectively sealed and connected to the heat exchange tube holes 10. The heat exchange tube 9 is sealed and connected to the heat exchange tube holes 10 reserved in the annular baffle 5 and the louvered baffle 6. The heat exchange tube 9 passes through the heat exchange tube holes 10 reserved in the annular baffle 5 and the louvered baffle 6.

[0030] like Figure 1 and Figure 2 As shown, a baffle plate is provided inside the heat exchanger shell 1. The baffle plate includes an annular baffle plate 5 and a louvered baffle plate 6. The annular baffle plate 5 is provided with a heat exchange tube hole 10 for the heat exchange tube 9 to pass through, and the louvered baffle plate 6 is provided with a heat exchange tube hole 10 for the heat exchange tube 9 to pass through. The annular baffle plate 5 and the louvered baffle plate 6 are arranged alternately at intervals.

[0031] Based on the above structure, the tube-side fluid can enter the upper part of the left end cap 3 through the tube-side inlet pipe 8, then sequentially enter the heat exchange tube 9, the right end cap 301, then pass through the lower part of the left end cap 3, and finally flow out from the tube-side outlet pipe 801. The shell-side fluid first enters the heat exchanger shell 1 through the shell-side inlet pipe 2, and then flows out through the shell-side outlet pipe 201. A circular baffle 5 and a louvered baffle 6 are fixedly provided on the inner wall of the heat exchanger shell 1. The circular baffle 5 has heat exchange tube holes 10 adapted to the heat exchange tubes, and the heat exchange tubes 9 are inserted into the heat exchange tube holes 10. The louvered baffle 6 has heat exchange tube holes 10 adapted to the heat exchange tubes 9, and the heat exchange tubes 9 are inserted into the heat exchange tube holes 10. The circular baffle 5 and the louvered baffle 6 are alternately arranged inside the heat exchanger shell 1.

[0032] This invention optimizes the traditional disc-annular baffle shell-and-tube heat exchanger by addressing its drawbacks, such as large flow dead zones, tube vibration susceptibility, and high pressure drop. It replaces the annular baffle 5 with louvered baffles 6, resulting in a dual-type baffle shell-and-tube heat exchanger with fewer flow dead zones and lower pressure drop. This dual-type baffle shell-and-tube heat exchanger exhibits superior overall performance compared to the traditional disc-annular baffle shell-and-tube heat exchanger. This dual-type baffle shell-and-tube heat exchanger can be a fixed tubesheet type, a floating head type, or a U-tube type heat exchanger. Replacing the annular baffle 5 with louvered baffles 6 alters the fluid flow direction and velocity, enhancing shell-side heat transfer. The alternating arrangement of louvered baffles 6 and annular baffles 5 inside the heat exchanger shell 1 effectively reduces the flow dead zone in traditional baffle shell-and-tube heat exchangers and lowers the pressure drop of the shell-side fluid. On the other hand, it enhances the support for the heat exchange tubes 9 and reduces fluid-induced vibration.

[0033] like Figure 2 As shown, the annular baffle 5 and the louvered baffle 6 are alternately fixed inside the heat exchanger shell 1. L1 is the vertical distance between the left tube sheet 4 and the left louvered baffle 6 (266 mm in this embodiment), L3 is the vertical distance between the right tube sheet 401 and the right annular baffle 5 (288 mm in this embodiment), L2 is the width of the louvered baffle 6 (59 mm in this embodiment), and L4 is the thickness of the annular baffle 5 (5 mm in this embodiment). L1 and L3 can be determined according to actual needs.

[0034] Preferably, the number of annular baffles 5 and louvered baffles 6 are equal. In this way, when the shell-side fluid enters the double-baffle shell-and-tube heat exchanger, it first passes through the annular baffles 5 to form radial flow, and then passes through the louvered baffles 6, changing the flow direction and velocity, thereby enhancing shell-side heat transfer. Entering first through the annular baffles 5 does not obstruct fluid flow.

[0035] See Figure 2 and Figure 4 The louvered baffle 6 includes an annular housing 13, a fixing rod 11, and blades 12. The fixing rod 11 is disposed between the blades 12 and the annular housing 13, and the side of the blades 12 is in contact with and fixed to the annular housing 13. (See also...) Figure 4 In this embodiment, the louvered baffle 6 is provided with three blades 12. A complete heat exchange tube hole 10 is provided on the first blade 12. The lower semi-circular notch of the first blade 12 and the upper semi-circular notch of the second blade 12 form a heat exchange tube hole 10. The lower semi-circular notch of the second blade 12 and the upper semi-circular notch of the third blade 12 form a heat exchange tube hole 10. A complete heat exchange tube hole 10 is provided on the third blade 12.

[0036] See Figure 5 The annular baffle plate 5 in this invention is provided with heat exchange tube holes 10.

[0037] For an even better option, see [link to previous section]. Figure 4 The louvered baffle 6 has four fixing rods 11, with two fixing rods 11 respectively installed on the upper and lower parts of the annular shell 13. One end of the fixing rod 11 is fixed to the annular shell 13, and the other end is fixed to the blade 12. The fixing rods 11 serve two purposes: firstly, they reinforce the blade 12 and improve its stability; secondly, they create turbulence as the fluid passes through the upper and lower parts of the louvered baffle, enhancing shell-side heat transfer.

[0038] Among them, see Figure 1 The plane of the annular baffle 5 is perpendicular to the length direction of the heat exchange tube 9, and the blades 12 of the louvered baffle 6 are inclined relative to the length direction of the heat exchange tube 9. The inclined arrangement of the blades 12 of the louvered baffle 6 can better generate turbulence.

[0039] More preferably, the angle between the blades 12 of the louvered baffle 6 and the length direction of the heat exchange tube 9 is 45 degrees.

[0040] See Figure 2 and Figure 4 The louvered baffle 6 has three blades 12, and the three blades 12 have the same tilt direction and tilt angle. The blades 12 of the louvered baffle 6 are placed in the center. The vertical distance L5 from the center point of the middle blade 12 (the second blade 12) of the louvered baffle 6 to the upper wall of the heat exchanger shell 1 is equal to the vertical distance L6 from the center point to the lower wall of the heat exchanger shell 1, that is, L5=L6.

[0041] In one embodiment, see Figure 3 The heat exchanger shell 1 has a partition plate 7 inside the left end cap 3. The partition plate 7 cooperates with the left tube sheet 4 to divide the left end cap 3 into two chambers. A tube inlet pipe 8 is provided at the upper end of the left end cap 3, and a tube outlet pipe 801 is provided at the lower end of the left end cap 3.

[0042] More preferably, the heat exchange tube 9 is a circular tube, and all the heat exchange tubes 9 are arranged in an equilateral triangle.

[0043] like Figure 6-8As shown, the Nusselt number and overall performance evaluation (PEC) of the double-type baffle shell-and-tube heat exchanger with louvered baffles 6 and annular baffles 5 arranged alternately are higher than those of the disc-annular baffle structure shell-and-tube heat exchanger at different Reynolds numbers. Furthermore, the PEC is consistently greater than 1, indicating that the overall performance of the double-type baffle shell-and-tube heat exchanger is better than that of the disc-annular baffle structure. (Overall performance evaluation) ,in It is a Nusselt number. It is the coefficient of friction, where It can be calculated using ANSYS Fluent; and the shell-side pressure drop of the double-type baffle shell-and-tube heat exchanger with louvered baffles 6 and annular baffles 5 arranged at intervals is also less than that of the shell-and-tube heat exchanger with a disc-annular baffle structure.

[0044] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0045] The parts of this invention not described in detail are well-known in the art. The above embodiments are provided merely for the purpose of describing the invention and are not intended to limit the scope of the invention. The scope of the invention is defined by the appended claims. All equivalent substitutions and modifications made without departing from the spirit and principles of the invention should be covered within the scope of the invention.

Claims

1. A double-baffle shell-and-tube heat exchanger, comprising a heat exchanger shell, a shell-side inlet pipe, a shell-side outlet pipe, end caps, and heat exchange tubes, characterized in that, The heat exchanger shell is equipped with baffles, including annular baffles and louvered baffles; the annular baffles are provided with heat exchange tube holes for the heat exchange tubes to pass through, and the louvered baffles are provided with heat exchange tube holes for the heat exchange tubes to pass through, and the annular baffles and the louvered baffles are arranged alternately at intervals.

2. The dual-type baffle shell-and-tube heat exchanger according to claim 1, characterized in that, The number of the annular baffles is equal to the number of the louvered baffles.

3. The dual-type baffle shell-and-tube heat exchanger according to claim 1, characterized in that, The louvered baffle includes an annular housing, a fixing rod, and blades. The fixing rod is disposed between the blades and the annular housing, and the side of the blades is in contact with and fixed to the annular housing.

4. The dual-type baffle shell-and-tube heat exchanger according to claim 3, characterized in that, There are four fixing rods, with two fixing rods respectively provided on the upper and lower parts of the annular shell.

5. The dual-type baffle shell-and-tube heat exchanger according to claim 3, characterized in that, The plane of the annular baffle is perpendicular to the length direction of the heat exchange tube, and the blades of the louvered baffle are inclined relative to the length direction of the heat exchange tube.

6. The dual-type baffle shell-and-tube heat exchanger according to claim 5, characterized in that, The angle between the blades of the louvered baffle and the length direction of the heat exchange tube is 45 degrees.

7. The dual-type baffle shell-and-tube heat exchanger according to claim 3, characterized in that, The louvered baffle has three blades, and the three blades have the same tilt direction and tilt angle, with the blades placed in the center.

8. A double-baffle shell-and-tube heat exchanger according to claim 1, characterized in that, When the shell-side fluid enters the dual-type baffle shell-and-tube heat exchanger, it first contacts the annular baffle and then the louvered baffle.

9. The dual-type baffle shell-and-tube heat exchanger according to any one of claims 1 to 8, characterized in that, The heat exchanger shell has a partition plate inside the left end cap. The partition plate works with the left tube sheet to divide the left end cap into two chambers. A tube inlet pipe is provided at the upper end of the left end cap, and a tube outlet pipe is provided at the lower end of the left end cap.

10. The dual-type baffle shell-and-tube heat exchanger according to claim 9, characterized in that, The heat exchange tubes are circular tubes, and all the heat exchange tubes are arranged in an equilateral triangle.

Images